Contact engineering of single core/shell SiC/SiO2 nanowire memory unit with high current tolerance using focused femtosecond laser irradiation.
Contact engineering of single core/shell SiC/SiO2 nanowire memory unit with high current tolerance using focused femtosecond laser irradiation.
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DOI：
10.1039/c9nr10690a
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发表时间：
2020-02
期刊：
影响因子：
6.7
通讯作者：
Luchan Lin;Jinpeng Huo;Peng Peng-Peng;G. Zou;Lei Liu;W. Duley;Y. Zhou
中科院分区：
文献类型：
--
作者：
Luchan Lin;Jinpeng Huo;Peng Peng-Peng;G. Zou;Lei Liu;W. Duley;Y. Zhou
单纳米线存储单元在高密度纳米电子电路的设计中特别有意义，但由于弱接触状态而导致的性能仍然是一个主要问题。本文采用飞秒激光局部接触工程的方法，实现了核/壳结构SiC/SiO2纳米线与Au电极的键合。由于等离子体增强的光吸收可以定位在金属氧化物（Au-SiO2）界面处，因此优化的异质结（Au-SiO2-SiC）是可能的。在纳米线电路中，穿过势垒的电子输运和氧化物-半导体（SiO2-SiC）界面处的电荷积累得到改善。仅在一个偏置周期（“写入”）之后就可以实现快速且稳定的电阻变化，并且可以在低电压（<0.5 V）下读取/提取写入状态。与其他已建成的纳米线电路不同，在没有外部电源的情况下，电阻状态可以保持10分钟，这表明这些器件可以用于短期存储单元。高电流耐受性也通过用于保护内部SiC芯的表面氧化物壳在电路中提供。单根SiC/SiO2纳米线电路在击穿前的电流密度可达1.3 × 106 Acm-2，击穿过程为两阶段过程。
Single nanowire memory units are of particular interest in the design of high-density nanoelectronic circuits, but the performance due to weak contact state remains a major problem. In this paper, bonding between core/shell SiC/SiO2 nanowire and Au electrodes can be improved via local contact engineering with femtosecond (fs) laser irradiation. An optimized heterojunction (Au-SiO2-SiC) is possible since plasmonic enhanced optical absorption can be localized at the metal-oxide (Au-SiO2) interface. Electron transport across the barrier and charge accumulation at the oxide-semiconductor (SiO2-SiC) interface are improved in nanowire circuits. A fast and stable resistance change can be achieved after only one biasing cycle ('write') and the written state can be read/extracted at a low voltage (∼ 0.5 V). Unlike other as-built nanowire circuits, the resistance state can be retained for 10 min in the absence of external power, indicating that these devices can be used for short-term memory units. High current tolerance is also provided in the circuit by the surface oxide shell which acts to protect the inner SiC core. The current density carried by the single SiC/SiO2 nanowire circuit can be as high as ∼3 × 106 A cm-2 before break down, and that breakdown occurs as a two-stage process.